Early male touch fastener products were generally woven materials, with hooks formed by cut filament loops. More recently, arrays of very small touch fastener elements have been formed by molding the fastener elements, or at least the stems of the elements, of resin forming an interconnecting sheet of material. Typically a series of adjacent rows of male fastener components forms one side or element of a fastener closure and a mating female fastener component provides a field of loops or anchored fibers with which the male fasteners engage.
In most applications, male fastener elements are designed to releasably engage with the mating female fastener component. To engage the loops, the male fastener elements must penetrate the field of fibers at least until the tips of the engaging fastener element heads have sufficiently extended beyond some of the fibers, such that the fibers can be engaged within the crooks of the heads.
Subsequent to engagement, retention of an engaged fiber or loop depends, at least for loads within the ability of the loop to resist breakage, upon the head's resistance to distention and/or breakage. Distention is the opening of the crook under load of an engaged loop. For high cycle life applications, breakage of loops and heads is undesirable. Thus, the ability of the fastening to resist peel loads in such applications is generally limited by the ability of the head to resist distention.
Unfortunately, for many applications increasing the rigidity of heads designed for maximum loop penetration, to increase their peel resistance, is either undesirable or impractical. For example, many applications require a gentle ‘feel’ of the male fastener element array against the skin.
Further improvements in the overall design of male fastener elements, particularly those formed or molded of resin and arranged in large numbers upon a surface for engaging loops or fibers, are desired. Preferably, such improved fastener elements will be readily and efficiently manufacturable without great advances in manufacturing methods.